This is PSOBB Episode 4 monsters that only appears in Subterranean Desert 2 & 3. To come to think of it I hate this monster the most, they hop around, they can cast Gibarta and freeze you, they can jab you, they can flop and slam you to the ground and evades your attacks by jumping on the other side. They're usually pink but if you see the ones in "GREEN" colored, you have found the Rare Monster, Merissa AA.
Merissa A are said to be common that one of them seems to be different. Such as common Sand Rappys which will likely occur a Del Rappy. Good luck and comment if you think they are annoying or not.